Re-Engineering Main Engineering: The Evolution of the Engine Room in the Original Star Trek Television Series

by Greg Tyler

June 13, 2004

Updated January 1, 2006

One might expect a starship of the future to experience a number of upgrades and overhauls during its operational lifetime. In the fictional future of the original Star Trek television series, the USS Enterprise NCC-1701 would be no exception. As a creation for a 20th-century television production, however, the Enterprise's features and appearance was governed primarily by dramatic and budgetary necessities rather than by technological advances. Perhaps no interior space within the Enterprise demonstrates this more clearly than the ship's engine room.

The engine room of the USS Enterprise NCC-1701 was where Lieutenant Commander Montgomery Scott minded his bairns and saved the ship from destruction countless times during the ship's historic five-year mission. Amazingly the engine room was seen in only 26 of the 79 episodes of the original Star Trek television series. During that time the engine room saw a number of changes, some minor, some not so minor. This article will document all observable changes in the engine room from Star Trek's USS Enterprise.

In its first appearance, the Enterprise engine room was depicted as a large, almost cavernous facility. In addition to the room's high ceiling, clever camera angles, large foreground set props, and forced-perspective background elements added to the apparent scale of the room.

As seen in "The Enemy Within," the engine room had a grated window in the far wall, behind which was a set of tubes and conduits of various sizes and orientations. For the purposes of discussion, this article will refer to the area beyond the grated window as the pipe chamber. Assuming this grated window wall was oriented toward the back of the Enterprise, to forward and port of the grated window wall stood two large, seemingly identical contraptions that this article will refer to as transformers. The transformers were arranged fore-to-aft, and they were oriented in the same direction, with giant blue tubes facing inward, and plain, flat surfaces facing outward. The starboard side of the room featured a row of what appeared to be instrumentation.

Because the engine room scene in "The Enemy Within" required good Kirk, evil Kirk, and Spock to remain obscured from view at various points in the scene, the episode's set builders constructed a wall of screened panels for this episode. Among the screened panels is a "circuitry junction," constructed so that evil Kirk would damage it with his phaser. This circuitry junction never again appeared in the Enterprise's engine room. Perhaps Scotty decided to relocate the apparently crucial hardware to a more protected area, such as behind a solid wall!

Somewhat off-topic, Thomas Sasser of Thomas Models pointed out to this author that the damaged circuitry junction set piece reappeared in at least two episodes: as the damaged machinery housing in "The Devil in the Dark," and within the USS Constellation engine room in "The Doomsday Machine."

Thomas Sasser of Thomas Models has observed that the transformers seem to be of slightly different sizes. In the image above, it appears that the transformer farther from the camera is slightly smaller, and has differently sized pipes near the base of the unit. In other shots, particularly focusing on the back sides of the transformers, the transformers seem to be the same size. This would seem to suggest that the transformers were intended to appear to be of identical size and shape, as they are depicted in the soundstage diagram published in The Making of Star Trek.

To provide a sense of perspective to the diagram above, here's a run-down of the action from the engine room scene in "The Enemy Within."

Good Kirk and Spock proceed along the center of the engine room toward the grated window wall. Unbeknownst to them, evil Kirk is hiding atop transformer #2.

Good Kirk and Spock pause between transformer #1 and transformer #2. As evil Kirk watches from atop transformer #2, good Kirk and Spock split up. Spock walks between transformer #1 and transformer #2 toward the screen wall, and good Kirk continues to walk toward the grated wall.

After walking between transformer #1 and transformer #2, Spock proceeds ahead and slightly to the right, toward the screen wall. Evil Kirk then drops down to the floor between transformer #1 and transformer #2.

In the next shot, Spock appears to walk back toward the grated wall, while standing close to the transformers. Note that this is likely a camera trick. He is supposed to be walking away from the grated wall. The transformers are a more interesting background than the screen wall.

Good Kirk reaches the grated wall past transformer #2, and then turns right. Unbeknownst to good Kirk, evil Kirk is following him.

Good Kirk proceeds along the grated wall, and then turns right and walks behind the screen wall. Soon after, he realizes that evil Kirk is following him.

Good Kirk re-emerges from behind the screen wall, and evil Kirk begins walking between transformer #2 and the screen wall, away from the grated wall and toward the wall with the circuitry panel wall display. Good Kirk follows evil Kirk.

Evil Kirk continues to back along transformer #2 and transformer #1, toward the wall with the circuitry panel wall display. Just as evil Kirk prepares to shoot good Kirk, Spock emerges from behind transformer #1 and nerve-pinches evil Kirk, whose phaser beam misses good Kirk and impacts a circuit panel located near the screen wall.

The engine room became the province of "Captain" Kevin Thomas Riley in "The Naked Time." The engine room not only gained a live musician -- it also gained a console, a chair, and what appears to be a contradiction.

In wide shots of the engine room, the two transformers can be seen to have been shifted about one foot to the right. In the wide shot from "The Enemy Within," the transformers slightly obscured the grated window; here, they do not. A new cylindrical item, which will be called a "fire hydrant" for ease of reference, has been added to the grated window wall, below and to the left of the window. The upper row of the two rows of horizontal pipes in the pipe chamber have been decorated with black text.

Kirk and Scotty attempt to cold-start the engines using a matter/antimatter implosion.

Kevin Riley commandeers the Enterprise from within the engine room, seated at a console newly added beneath the "circuitry panel wall display." The console resides in a corner of the room, and it seems likely that the wall perpendicular to the wall with the circuitry panel wall display was added for this episode. This is because, if extended for more than a few feet, this wall would seem to occupy roughly the same location as the screen wall from "The Enemy Within."

"The Naked Time" is also the first time that the audience sees the entrance to the engine room. It is possible that the entrance was constructed for "The Enemy Within," but this seems unlikely, as it was never featured in the episode, and the expense of the engine room elements seen in "The Enemy Within" already seems high, given the large size and complexity of the set.

When one observes how much space there seems to be for the new console and Riley's chair, and how little space there was between transformer #1 and the circuity panel wall display in "The Enemy Within," it seems likely that transformer #1 was moved throughout the filming of "The Naked Time." In wide shots, transformer #1 was positioned in line with transformer #2, similar to the configuration in "The Enemy Within," and in closer shots of Riley seated at the new console, transformer #1 was probably moved out of the way.

It should be noted that in this episode, Spock is seen to walk to the entrance to the engine room, and the surroundings during his walk suggest that the engine room's entrance lies along a curved corridor, and that the engine room lies immediately outboard of the corridor. This author has doubts that the entrance as seen from outside the room is the entrance as seen from within the engine room set. In later episodes, the engine room has a foyer between the main area and the curved corridor, and the dimensions of the main engine room area do not appear to have been changed. The only ways that both the pre-foyer and post-foyer versions of the engine room set could be adjacent to a curved corridor would be if the entire curved corridor were later moved in order to accommodate the foyer, or if the entire engine room were moved were later moved in order to accommodate the foyer. The curved corridor was adjacent to a variety of other sets, so moving it would have been impractical. The engine room would have been more easily moved in order to accommodate the foyer, but it also seems impractical to move. The grated window wall is enormous -- seemingly twenty feet or more in height. Because of this, it is likely that the wall and the ceiling of the set were both anchored to the rafters of the soundstage. Moving these structures in order to accommodate a tiny foyer would seem to be cost-prohibitve. It is more likely that the engine room set's entrance in early episodes was not adjacent to a curved corridor, and that scenes showing the entrance from outside the room actually made use of an alternate doorway.

In this episode, Riley seems to have made his accommodations in the engine room more comfortable. Where there was once a wall, there is now sufficient space for a table to hold a tray of food. Three chairs have been added along the instrumentation panels.

Riley entertains himself in engineering, made easier by his new table and food tray.

The engine room seems to have undergone three additional changes:

The fire hydrant from "The Naked Time" has disappeared.

The pipe chamber now contains a third row of horizontal pipes. The uppermost row of pipes remain labeled as they were in "The Naked Time," the other rows remain unlabeled. Thomas Sasser of Thomas Models has stated a belief that the pipe chamber always had three rows of horizontal pipes. Observation of the pipe chamber in various episodes can neither validate nor invalidate this belief; however, it seems that the pipe chamber set piece was positioned at a lower elevation in earlier episodes. If three rows of horizontal pipes did exist in earlier episodes, then the bottom-most row of horizontal pipes would have been obscured by the wall below the grated window.

A more subtle change is that transformer #1 has been rotated ninety degrees. The camera never reveals whether transformer #2 is present in the engine room during the events of this episode.

In "Court-Martial," the transformers return to their normal orientation, although they are again shifted to the right. The transformers are also positioned closer together. These movements were done presumably to allow room for the console that was added in "The Naked Time." The three chairs from "The Conscience of the King" have vanished, and there also seems to be no sign of the table or Riley's food tray.

Interestingly records officer Finney's technical know-how seems to know no bounds. In addition to tapping out the ship's primary energy circuits, he can also remotely operate the ship's transporter. When Kirk enters the engine room, a corner near the entrance is empty, but when Kirk and Finney fight shortly afterward, a small table appears with a wrench lying on top of it. Finney uses this wrench to threaten the good captain.

The console that normally resides beneath the circuitry panel wall display has moved back to that position. Two indicator lights have also appeared on the wall to the right of the console. The lower, green light appears to indicate normal status, while the upper, amber light flashes to indicate an overload in progress.

The two-paneled, angled wall just inside and to the right of the main entrance appears to be wider than in previous appearances. A wall detail visible in "The Naked Time" has vanished. There is also now a prominent, rectangular "support column" at the corner of the angled wall and the wall containing the circuitry panel wall display. This column may have been present in previous stories like "The Naked Time," but it appears to be more prominent in this episode.

Due of the increased width of the angled wall, it seems unlikely that both transformers would fit in the length of the room between the circuitry panel wall display and the wall with the grated window. Except for some insert shots of Khan, the transformers appear to be absent during much of the fight between Kirk and Khan. In the insert shots, only a single transformer is seen. This suggests that there is only one transformer, located farther away from the instrumentation panels than in previous episodes.

Technically the Enterprise's engine room wasn't featured in this episode. The engine room set was, however, redressed to serve as the engine room of the Enterprise's sister ship, the USS Constellation.

"The Doomsday Machine" was not the first time that the engine room set was redressed to represent locations other than the Enterprise's engine room.

In "Charlie X," parts of the engine room set were used to represent a gymnasium aboard the Enterprise.

In "Balance of Terror," parts of the engine room set were used to represent the forward phaser control room aboard the Enterprise.

In "The Menagerie," the engine room set was redressed to represent a computer facility on Starbase 11.

For this episode, the engine room set underwent its first major "persistent" upgrade. It is probably no coincidence that the change occurred while the set represented a room other than the Enterprise's engine room. As described in the Wikipedia, "in film, a redress is the redecoration of an existing movie set, so that it can double for another set. This saves the trouble and expense of constructing a second set." Some of the money saved by redressing the existing engine room set for the Constellation's engine room rather than building a new set from scratch would seem to have been used to upgrade the set for subsequent use as the Enterprise's engine room.

Major Upgrade #1: Redesigned "Instrumentation Panels" Wall

Prior to this episode, the Enterprise engine room's "instrumentation panels" wall was a continuous bank of hand controls and data displays. This bank of consoles was comprised of three adjacent units.

Also prior to this episode, the area above the wall was basically a fancy-looking flat. The best glimpses of the old version of the wall above the data displays are in "The Naked Time" and in "The Menagerie," when the set was redressed to represent a Starbase 11 computer facility.

Beginning in this episode, the "instrumentation panels" wall has lost one of its three adjacent units. The former position of Unit #2 is now occupied by a steep staircase with handrails. The data displays that once belonged to Unit #2 now belong to Unit#3, and the data displays that once belonged to Unit #3 are no longer present in the set. The remaining data displays have been redecorated, and a new plant-on detail has been added to each data display. The hand controls of the remaining instrumentation panel units have either been heavily altered or entirely replaced. New "greeblies" have been added below the hand controls.

(Note: Many of these images have been contrast-enhanced, since the set was minimally lit in this episode.)

Note that the stairway seems to be narrower than the instrumentation panel unit that it replaced. This might imply that the engine room has been compressed in length. Since the grilled wall was very tall and was likely anchored to the soundstage ceiling, if the engine room's length was in fact compressed, the opposing wall area -- including the entrance to the engine room -- was probably moved.

The area above the instrumentation panels' data displays has also changed radically. The somewhat bland former wall details have been replaced by an inset walkway with handrails that join with the handrails of the new staircase. A "booth" now exists at the end near the grilled wall. The booth has twin rectangular windows that overlook the bulk of the engine room. A single-pocket door provides access to the booth. Subsequent episodes make clear that there is also a single-pocket door along the back wall of the booth, suggesting a never-seen room beyond the booth.

Major Upgrade #2: New Set Prop

The engine room now has a new set prop -- a two-lobed gizmo with a box-shaped center connector. For discussion purposes this prop will be referred to as "floor binoculars."

Each lobe of the floor binoculars has a "clipped-corner triangular" plan outline. A basketball-sized sphere is located at each corner, as well as on the top center of one of the lobes. A coaster-like object is located on the top center of the other lobe. A blue topper is mounted on the top of the center connector.

Major Upgrade #3: New Foyer

A new reddish grill acts as a divider between the main area of the engine room and a new "foyer." The ever-moving console now resides in a more or less permanent position, along one of the walls of the foyer. Although not clearly visible in this episode, the circuitry panel wall display has likely moved to one of the walls of this foyer, because it is seen there in all subsequent episodes.

Other Changes

In addition to the major changes, a variety of minor changes took place, not all of which necessarily persisted from episode to episode.

Facing the grilled wall, to the left of the grill are a new wall decorations: a "street light" greeblie, two "Doomsday boxes," a "Doomsday grill," and three vertical pipes.

Standing roughly in a typical location of one of the Transformers is a damaged circuitry junction, recycled from "The Enemy Within."

The area opposing the grilled wall has changed significantly. In addition to the new foyer, new greeblies can be seen near the instrumentation panels. In the usual prior location of the circuitry panel wall display is a new wall with an "inset tool cabinet." To the right of the cabinet is an inset control for the cabinet door. The door control is covered by a removable cover plate that has a handle.

The transformers seem to have vanished once again.

Recycled Footage

Three shots featuring the Constellation engine room is recycled footage that was originally filmed for "Tomorrow Is Yesterday." Following a newly filmed shot of Scotty standing at an instrumentation panel, Kirk orders Scotty to send the damaged Constellation "full ahead." After the acceleration sends Kirk flying around auxiliary control, the first recycled shot occurs, showing Scotty being tossed from the instrumentation panel wall to a console in the middle of the engine room. The second shot follows shortly afterward, with Scotty clinging to the console as the engine room shakes. The third shot shows Scotty clinging to the grill on the grilled wall as the room shakes. All subsequent shots are newly filmed for the episode. Although the "Tomorrow Is Yesterday" Enterprise engine room differs in layout from the Constellation engine room, the context of the new and recycled shots indicates that Scotty is supposed to be in the same room throughout the sequence.

Set Redress - Auxiliary Control Room

Parts of the ehe engine room set serve double-duty in this episode. "Unit #3" of the instrumentation panels appears in the background of the Constellation's auxiliary control room.

Opinions expressed by interviewees are their own, and they do not necessarily
represent the opinions of the authors of this web site. The authors of this web site cannot
always verify and are not responsible for the accuracy of claims made by interviewees.